Process of uniting a plurality of yarns into a network structure and the resulting unitary yarn structures



Feb. 11, 1964 l 'A. L. BREEN 3,120,733 PROCESS OF UNITING A PLURALITY 0F YARN NTO A.

NETWORK STRUCT AND THE RESULTI UNITARY N STRUCTURES Filed July 6, 1962 3 Sheets-Sheet 1 FIG.

INVENTOR ALVIN L. BREEN ATTORNEY Fgb. 11, 1964 A. 1.. BREEN 3,120,733 PROCESS OF 1111111111; A PLURALITY 0F YARNS INTO A.

NETWORK STRUCT AN HE RESULTING UNITARY N S CTURES Filed July 6, 1962 FI6.4 FIG. 5 FIG. 7

FIG.9

INVENTOR ALVIN L. BREEN ATTORNEY 1964 A. L. BREEN 3, 20,733

PROCESS OF UNITING A PLURALITY 0F YARNS INTO A v NETWORK STRUCTURE AND THE RESULTING UNITARY YARN sTRUcTUREs Filed July 6, 1962 3 Sheets-Sheet 5 FIG. I!

TREATIENI INVENTOR ALVIN L. BREEN ATTORNEY United States Patent M 3,120,733 PRGQESS (BF UNITING A PLURALITY 0F YARNS IWTU A NETWORK STRUCTURE AND THE RE- SEJLTING UNHTARY YARN STRUCTURES Alvin L. lireen, Wilmington, DeL, assignor to E. I. du Pont de Nemours and Company, Wilmington, Del., a corporation of Delaware Filed July 6, 1962, Ser. No. 207,966 15 Claims. (Cl. 57-140) This invention relates to a process for combining a plurality of false twisted yarns into a unitary structure and to the novel yarn assemblies produced. It is more particularly concerned with combining yarns without the use of true twist or adhesive to form a firmly integrated structure in which the identity of the individual yarns is maintained, and so that the assembly can readily be separated into the original yarns without entanglement.

In the spinning of synthetic organic filaments from melt or solution, each spinneret produces a zero twist yarn. Bunting et al. US. Patent No. 2,985,995, issued May 30, 1961, discloses a method of interlacing the filaments at high speed to produce a unitary yarn without the necessity of using the conventional slow processes of sizing or introducing true twist. The interlacing process can be combined with high speed spinning processes to produce yarn, suitable for shipment to customers, in a continuous operation. Another way of accomplishing this, by introducing alternating twist at high speed instead of interlacing, is disclosed in Daniels et al. US. Patent No. 3,022,566, issued February 27, 1962. However, additional filaments treatments are frequently required before shipment and have conventionally been conducted on tows, each of which is composed of a great number of filaments from a plurality of spinnerets. The groups of filaments from different spinnerets are mingled and lose their identity in conventional tows, which are nonunitary assemblies of parallel filaments that must be regrouped into yarns after treatment in tow form.

It is an object of this invention to provide a process for producing a unitary tow, or other assembly of a large number of filaments, by uniting a plurality of groups of filaments so as to bind them together without the use of true twist or filament adhesion. Another object is to provide such a process in which the individuality of the filament groups is preserved and the assembly can be separated into the original groups without difficulty with filament entanglement. A further object is to provide a tow or other structure of assembled filaments wherein the filaments are grouped into yarns held firmly together without true twist or adhesive. A still further object is to provide such a structure wherein there is substantially zero net twist in the individual yarns and in the structure as a whole. Other objects will become apparent from the specification and claims.

In accordance with this invention it has been found that yarns can be caused to false twist together due to twist liveliness introduced by intermittently false twisting the individual yarns into a temporary alternating S and Z twist configuration and bringing the yarns together while still twisted. Twist liveliness cause the yarn to attempt to untwist so as to remove the alternating twist. This twist energy causes contacting yarns to twist together at portions which untwist in the same direction. Other contacting portions which are twisted in opposite directions are free to untwist without twisting about each other. This is utilized in the process of this invention by introducing intermittent false twist into a plurality of yarns so as to provide portions of corresponding twist along adjacent yarns, and contacting individual yarns alternately with adjacent yarns in a programmed sequence to 3,120,733 Patented Feb. 11, 1964 unite the yarns into a unitary structure by a network of intertwists between portions having twist correspondence.

The above process is especially useful for the production of novel nonwoven unitary structures which are suitable for further processing in the manner conventional with tows, or in the same way as woven fabric. These can be prepared in either flat fabric or tubular form so that they can readily be taken apart into yarn, and are in a unitary form which avoids problems in processing or packaging zero twist yarn or tow. The novel products may also be used in fabric form as netting, cheesecloth, backing fabrics, insulation and other textile uses.

These novel fabric structures consist of generally parallel yarns having intermittent portions along each yarn twisted with corresponding portions of adjacent yarns to form a net-like assembly having a repeating pattern of periodically intertwisted yarns. Each interior yarn of the assembly is twisted alternately with the two yarns adjacent to it on each side, and the outermost yarn on each side of a fiat structure is periodically twisted with the single yarn adjacent to it. The network structure has an appearance suggestive of chicken wire fencing but differs in important respects, especially in the ease with which the structure can be taken apart. If entanglement of fibers at zero twist portions of the yarns is avoided, the structure can simply be pulled apart to separate the original yarns. If the original yarns used have zero twist, then the yarn filaments can also be separated by completely removing the false twist.

Entanglement of fibers can be avoided by staggering the zero twist portions of adjacent yarns, or by providing sufficient true twist in addition to the false twist so that there are no zero twist portions. Preservation of yarn unity to avoid entanglement can also be assisted by fiber interlacing within the yarn bundles. Combinations of these can, of course, be used to help preserve the identity of the individual yarns. When a high energy of twist liveliness is introduced by false twisting, the energy is expended not only in forming the above network structure but, to a small extent, in rope cabling. This more compact structure is desirable to provide good piddling during tow processing.

In the drawings, which illustrate specific embodiments of the invention,

FIGURE 1 is a simple schematic view of a yarn twisted alternately with adjacent yarns to form one unit of the repeating pattern described above,

FIGURE 2 is a similar schematic view showing the repeating pattern in the product,

FIGURE 3 is a similar schematic view of an inphase tubular form of product,

FIGURE 4 is an end view of a single fluid torque jet suitable for applying false twist,

FIGURE 5 is a corresponding longitudinal cross section on the line 5-5 of FIGURE 4,

FIGURE 6 is a similar cross section of an interlacing jet used in certain process embodiments,

FIGURE 7 is a corresponding lateral cross section on line 7-7 of FIGURE 6,

FIGURE 8 is a cross-sectional view of a gang of torque jets, viewed in the same direction as the one shown in FIGURE 4, in combination with means for supplying fluid in a pulsating programmed sequence to intermittently false twist a plurality of yarns as described,

FIGURE 9 is a front elevational view of a slotted plate alternator for contacting intermittently false twisted yarns as described,

FIGURE 10 is a perspective view of an angled pin alternator for the same purpose as the alternator of FIG- URE 9, and

FIGURE 11 is a schematic plan view illustrating the 3 process of preparing the fabric of this invention with the gang of torque jets of FIGURE 8 and alternator of FIGURE 10, treating the fabric, and then separating the fabric into individual yarns.

The invention will now be described in greater detail with reference to the drawings. A yarn can be intermittently false twisted along its length by passing it through false twisting means operating on an interrupted cycle or operated to vary the direction of twist in an alternating cycle. A fluid torque jet is preferable for the purpose of the present invention, since intermittent or reversing twist can be introduced at high speed and readily controlled by a regulating valve in the fluid supply line or manifold. The fluid pressure can be caused to pulsate by interrupting the flow to the torque jet in an on-off cycle, or the torque direction can be caused to reverse cyclically by supplying fluid alternately in opposite tangential directions to the yarn passageway through the jet. In either case an alternating S and 2 direction of twist with intermediate portions of zero twist will be introduced into a zero twist yarn, the designation false twist being used to indicate that the net amount of twist is zero over continuous lengths of yarn. The intensity of false twist will be used in reference to the average twist value which would be calculated by ignoring the direction of twist. This is somewhat analogous to the root-mean-square value used in alternating current analysis. This false twist can, of course, be superimposed on a true twist to provide a yarn in which the twist level varies along its length but does not reverse in direction.

When a pair of false twisted yarns are brought into contact with each other, they will cable together where the twist directions is the same in the individual yarns. FIGURE 1 shows three such yarns which have been brought together in sequence so that yarns 1 and 2 have twisted together into a short cable 4, then yarns 2 and 3 have formed a cable 5, and finally yarns 1 and 2 have formed an additional cable 6. By continuing this alternate intermittent cabling action with a plurality of adjacent yarns 7, 8, 9, 10, 11, 12, etc, a network of yarns is produced as shown in FIGURE 2. The tubular network assembly of yarns shown in FIGURE 3 is formed by continuing the process around a cylindrical path in programmed sequence. The programmed cabling sequence used may be in-phase as shown in FIGURE 3 or out-ofphase as shown in FIGURE 2.

The cabling action is controlled by the length of the twist cycle or twist period along the yarns, the manner in which similarly twisted portions are staggered in adjacent yarns, and the intensity of false twist. A relatively close network is obtained with a short twist period, an in-phase programmed sequence and a high intensity of twist. Entanglement of adjacent zero twist portions of yarns may interfere with subsequent separation of the yarns, particularly with twist periods as great as yards or more. When this is not overcome by staggering the zero twist portions, entanglement can be minimized by introducing true twist or interlacing into the feed yarn before it is false twisted.

The fluid torque jet of FIGURES 4 and 5 is characterized by yarn passageway 17 intercepted by one or more fluid conduits 18 positioned to direct a fluid circumferentially about the inner periphery of yarn passageway 17. The yarn passageway is preferably cylindrical in form and fluid conduit 18 is positioned as shown in FIGURE 4 so that its longitudinal axis does not intersect the longitudinal axis of passageway 17. When gas under pressure is passed through fluid conduit 18 so that it leaves at least /2 sonic velocity upon emerging into yarn passageway 17, the force of the gas impinging upon any yarn within passageway 17 separates the filaments of the yarn momentarily while simultaneously applying sufficient torque to twist the yarn at a very high twisting rate, which may be of the order of 200,000 to 2,000,000 turns per minute. Fluid is supplied to fluid conduit 18 by any convenient means. Preferably, the yarn passageway will have beveled or rounded edges at both ends to minimize tearing of the yarn bundle. In accordance with the embodiment shown in FIGURES 4 and 5, the yarn passageway is widened by bevels r19 at the yarn entrance and exit ports.

In some instances as, for example, when the yarn passageway is of substantial length, it is desirable that the yarn passageway contain one or more fluid exhaust ports in order to facilitate removal of fluid from the yarn passageway. Similarly, the fluid twister may be designed to provide for ease in stringing up a threadline by pro viding a stringup slot running the entire length of the yarn passageway.

The interlacing jet shown in FIGURES 6 and 7 has an axial yarn passageway 20 which in this embodiment is substantially cylindrical in form throughout its length although, of course, it may have a different configuration as, for example, a slot, a slot with a rounded floor, etc. Fluid conduit 21 intercepts yarn passageway 20 at right angles to the wall thereof and positioned so that the longitudinal axes of fluid conduit 21 and of yarn passageway 20 intersect and, preferably, are perpendicular to each other.

The gang jet of FIGURE 8 is adapted for twisting a multiplicity of yarn ends intermittently or simultaneous ly, or according to any predetermined schedule. This gang jet possesses a plurality of yarn passageways 23 intercepted by a similar plurality of fluid conduits 24. The fluid conduits may be positioned relative to the yarn passageway so as to provide an interlacing jet or torque jct as desired. Each yarn passageway also is provided with a string-up slot 25 so that yarns may be strung up on-therun. Each of the fluid conduits communicates with a fluid manifold 26 by way of a rotatable helical valve 27. By suitable design of the valve and control of the rotation of the valve during operation of the jet, individual yarns passing through the jet may be twisted according to any desired predetermined schedule so that either inphase or out-of-phase networks may be produced. The helical valve is rotated by drive shaft 28 using any convenient power source.

FIGURES 9 and 10 show two species of alternators which, when used in conjunction with a suitable gang 'et, such as that of FIGURE 8, will operate to alternately twist each yarn in a yarn warp passing through' the gang jet successively and intermittently with each adjacent yarn in the warp to unite the yarns into a structure of this invention. Twist lively yarns 29 from the jet twister are passed in parallel through the alternator shown in FIGURE 9, each yarn being led through a separate slot opening 29. Movement of the alternator of FIGURE 9 upward to the position shown places yarns 29 at the bottom of slots 30, and a downward movement of the alternator will move yarns 29 to the tops of slots 30. In each position pairs of yarns are brought sufficiently close together so that the individual yarns exiting from a gang jet will intercept the nearest adjacent yarn and become securely but releasably intertwisted therewith. The jet twisting operation causes the yarns to vibrate, which assists in bringing the yarns into the desired intertwisting relationship. By regulating the cycle of the up and down movement of the alternator the desired period may be attained in the resulting yarn assembly.

The apparatus shown in FIGURE 10 embodies the above principle in a form which provides easy string-up with traveling yarns. The angled guide pins 31 are arranged to pair yarns alternately with adjacent yarns on each side in the same manner as the above slots. The pins are spayed in the direction of yarn travel so that continuous yarns can be threaded into place between pins without interrupting operation. Rows of pins are mounted in racks 32 which are supported for relative movement in a frame 33 to facilitate string-up and adjustment. The ends of the frame are secured to hearing blocks 34 and 35 which slide up and down on bearing rods 36 and 37, respectively. Springs 38 and 39 act to push these blocks upward until stopped by collars 4t) and 41 on the rods. Solenoids 42 and 43 under each end of the frame 33 are used to pull the frame downward against the action of the springs. The solenoids are arranged to be energized by an electric timer not shown) adjustable from 1 to 60 cycles per second with suitable on-oif cycles in synchronism with the action of the gang twister described in connection with FIGURE 8 to provide the desired programmed sequence of yarn pairing.

FIGURE 11 illustrates schematically the operation of the above apparatus to form a network yarn assembly, and the subsequent process steps of treating the assembly as a tow followed by separation into the original yarns. A plurality of separate yarns 29, which may be zero twist bundles of filaments from a plurality of spinnerets, are supplied at controlled speed through snubbing pins 49 to a fluid twister b of the type shown in FIGURE 8. The yarns are individually twisted alternately in S and 2 directions and pass immediately to alternator 51, of the type shown in FIGURE 20, where the yarns are caused to twist together to form the network assembly 52. This is initially in fiat fabric form suitable for treatment as any other fabric, but is usually more readily handled as a tow.

.The generally parallel intertwisted yarns of the assembly are brought together by passage between a pair of guide rolls 53 and 54 to form a tow bundle. The tow is then subjected to any conventional tow treatment, indicated generally by the rectangle 55. From this treatment the tow passes between rolls 56 and 57, which will usually be positively driven to control the tension. Guide rolls 53 and 54 may also be positively driven to control the tension prior to the treatment, as when a dilferent tension is used for forming the assembly. The treated yarns are then separated and pass through a series of guide pins 58. These pins are spaced at a distance which not only opens the tow to the network fabric structure, but also causes the yarns to be pulled apart, so that the structure reverts back to free yarns. The separated yarns pass from guide pins 58 to individual wind-ups 60. The yarns can also be taken up on a beam.

When pulled apart at a sufficient angle the intertwisted or cabled pairs of yarn will untwist and separate, since the intertwist results from a false or alternating twist having a net value of zero along the yarn length. For continuous tow-to-yarn separation the twist level in the yarns immediately prior to separation should average at least /2 turn per inch without regard for direction of alternating twist). If part of the twist intensity is lost during the treatment, as when a drawing operation is included, then a higher level should be introduced at twister 50. In general, an initial twist level in the range of 1 to 2 turns per inch average twist is needed to provide about /2 turn per inch average twist after drawing. Shorter false twist cycles provide better results during yarn separation than cyoles giving wave lengths in the range of 5 to yards. The twister 5t) and alternator 51 should be operated to provide 45 to 90 phasing of these twist waves where yarn pairs are intertwisted, i.e., so that zero twist portions of yarn pairs are staggered. Approximately 45 phasing is preferred, particularly at twist levels averaging /2 to 1 turn per inch, because the combined twist liveliness and resultant intertwisting between yarn pairs is greater than when the twists are 90 out-of-phase. The above considerations apply only when the yarns are to be separted, of course. Thus, in-phase twisting 0 phasing) may be desirable when the final product is the network fabric.

The following examples illustrate some of the specific embodiments of the invention.

Example 1 A warp of 48 ends of polyacrylonitrile yarn, each of 2200 denier and 250' filaments, is supplied from spinning cells at 230 yards per minute under a tension of 70 grams per yarn to a gang jet twister for processing as indicated in FIGURE 11. The jet twister, illustrated in FIGURE 8, is operated with air pressure at 30 p.s.i.g. to introduce alternating twist at an intensity averaging about 1 turn per inch, and a twist period of about 2.5 yards in '45 phase relationship between adjacent yarns. The alternator, illustrated in FIGURE 10, is operated so that alternating cabling occurs at periods of 15 yards, the long periods insuring development of well stabilized cabled yarn pairs. Flhe resulting warp assembly holds the yarns in substantially parallel relation by a network of intertwists which also maintainssufficient twist along the individual yarns to retain their identities. The assembly is then condensed into a tow rope and washed, drawn, crimped and dried by conventional tow treatment procedures. The treated tow is separated continuously into yarns of the same identity as the starting yarns but each now drawn to 750 denier and with about 8 filament crimps per inch. The separated yarns are wound into individual packages as indicated in FIGURE 11.

Example 2 A warp of spontaneously crimpable yarns composed of polyethylene terephthalate filaments is formed into an assembly as in Example l. The assembly is converged into a tow and piddled onto the moving belt of an air dryer and cnimped with hot air at C. The crimped, bulky tow is removed from the belt and piddled into a tow shipping container. This assembly can subsequently be separated into yarns, but is especially useful without separation for forming coherent interliners, padding, stuffing and the like.

Example 3 A warp of 200 denier, 68 filament, polyhexamethylene adipamide yarns is fed at 100 yards per minute to a gang jet twister and alternator combination similar to that of Example 1 but operated to provide an alternating cabling period of 6 inches. A flat network fabric structure is produced of the type illustrated in FIGURE 2. The fabric is readily spread to different widths to give a range of weights per unit area for uses such as netting and laminating reinforcement. Hot calendening at 180 C. heat-sets the fabric to stabilize it at the desired width.

Example 4 Example 3 is repeated but using a circular arrangement of jet twisters and alternator operated to produce an in-phase-twist, cylindrically shaped, network fabric as illustrated in FIGURE 3. A stable tubular structure suitable for covering elongated objects is formed.

Air at room temperature is preferred for twisting yarn in the fluid jets used in this invention, but the air may be heated or refrigerated, if desired. Steam, saturated or superheated, may also be used for economic reasons or where its plasticizing action, if any, is desired. Other gases such as carbon dioxide, nitrogen, and the like, may also be utilized. The invention is illustrated using air as a fluid because air is preferred in carrying out the process of this invention, but almost any economic fluid is suitable. -In order to operate the process in accordance with the invention, it is desirable that the velocity of jetted gas, immediately prior to impinging upon the yarn, reach a velocity of /2 sonic velocity or more so that, depending on the diameter of the yarn passageway, yarn tension, etc., twisting speeds of up to about 2,000,000 twist per minute can be easily obtained. For this purpose, air at a pressure of at least about 10 p.s.i.g. is usually sufficient, although frequently a pressure of about 30 p.s.i.g. or more is preferred, when operating at normal yarn tensions. Even lower pressures may be employed in those cases where the yarn tension is of a low order and/or low twist rates are desired.

Yarn tensions are not critical nor is the denier, number of filaments or chemical composition of the filamentary material. By proper selection of twister design and operating conditions the process of this invention can be carried out on any filirnentous structure at normal operating tension levels. It is preferred to operate at a tension high enough to prevent twist doubling and accompanying processing difficulty.

The ratio of yarn diameter (YD) to the diameter of the yarn passageway (YPD) of the twister determines to some extent the nature and efficiency of twisting; the ratio of YD to YPD should be from about 1:2 to about 1:10, and preferably about 1:4. The torsional modulus of the yarn determines the twist level at a given tension value.

The novel structure of this invention can be produced from any textile strands, including staple or continuous multifilament yarn, monofilarnents, thread, roving, and the like. Yarn has been referred to throughout the instant disclosure as exemplary of all such textile strands, since in the processing of yarn the invention has its greatest utility. The yarn or like structures may be composed either partially or entirely of synthetic polymeric materials, such as the polyamides (nylon), e.g., poly(e-caproamide) and poly(hexamethylene adipamide); polyesters, e.g., poly(ethylene terephthalate), poly(transpara-hexahydroxylylene terephthalate), poly- (ethylene terephthalate/ethylene isophthalate), etc., and acrylic polymers, such as poly(acrylonitrile) and/or any of the many copolymers thereof; vinyl polymers, e.g., poly(vinyl chloride), poly(vinylidene chloride), or copoiymers thereof; hydrocarbon polymers, such as polyethylene or polypropylene; and so on. The composition may be based on naturally occurring materials, including the cellulose esters, regenerated cellulose (rayon), regenerated protein, cotton, wool, silk, etc.

The process of this invention, especially when employed to consolidate or compact a yarn bundle for textile processing operations, results in improved yarn quality. Broken filaments and the like are twisted back into the yarn bundle eliminating subsequent wraps, stripbacks and the like. The process of this invention permits yarn production at exceedingly high twisting rates at exceedingly high throughput speeds over Wide ranges of tension, from zero tension to at least grams and up to grams or more. The susceptibility of the process to variations in yarn tension, speed, etc., during twisting permits a number of useful process departures from the more important embodiments of intermittent twisting, including production of alternating twist yarns by the controlled vairation of such factors during continuous unidirectional twisting. The process may be employed at most stages of textile operations, such as during beaming, spinning, drawing, and the like. Other advantages inherent in the practice of this invention will occur to those undertaking its practice.

Since many different embodiments of the invention may be made without departing from the spirit and scope thereof, it is to be understood that the invention is not limited by the specific illustrations except to the extent defined in the following claims.

I claim:

1. The process for uniting a warp of yarns into a network structure which comprises individually false twisting the yarns of the Warp intermittently along their lengths to provide twist lively portions of corresponding twist along adjacent yarns, and contacting twist lively portions of yarns alternately with those of adjacent yarns in a programmed sequence to unite the warp into a unitary structure by a network of intertwists between portions having twist correspondence.

2. A process as defined in claim 1 wherein the false twist is introduced with a yarn twister having a periodically reversing direction of twist.

3. A process as defined in claim 1 wherein the false twist is introduced with a jet twister supplied with pulsating fluid.

4. A process as defined in claim 1 wherein the false twist is introduced with a jet twister supplied with fluid in a periodically reversing twist direction.

5. A process as defined in claim 1 wherein the false twist is introduced in continuously moving yarns by a twisting cycle of zero to maximum 8 twist to zero to maximum 2 twist to zero in a repeating regular period along the yarns.

6. A process as defined in claim 5 wherein the periods in adjacent yarns are out-of-phase by up to about 7. A process as defined in claim 5 wherein the periods in adjacent yarns are about 45 to 90 out-of phase.

8. A process as defined in claim 5 wherein the periods are substantially in-phase across the warp.

9. In a tow treatment process wherein a plurality of filament bundles are assembled into a tow for treatment, the improved for assembling said filament bundles so that they can be reseparated from the tow after treatment which comprises individually false twisting parallel filiment bundles intermittently along their lengths to introduce an alternating twist into each bundle which averages at least /2 turn per inch and is about 45 to 90 out-ofphase with the twist period of adjacent bundles, immediately contacting filament bundles alternately with adjacent bundles to cause correspondingly twisted portions to twist together due to twist liveliness, and thereafter condensing the resulting assembly into a tow for treatment, for false twist acting to maintain the separate identities of the filament bundles during treatment and to minimize entanglement during reseparation.

10. A unitary assembly of a plurality of yarns having a repeating network pattern of yarns intertwisted alternately with adjacent, generally parallel yarns along their lengths, the intertwists being false twists removable by pulling the yarns apart.

11. A unitary assembly as defined in claim 10 in the form of a tow-like bundle of a large member of filaments.

12. A product as defined in claim 10 in the form of a flat fabric.

13. A product as defined in claim 10 wherein each yarn is false twisted in a repeating regular period and the periods in adjacent yarns are about 45 to 90 outof-phase.

14. A product as defined in claim 10 wherein each yarn is false twisted in a repeating regular period which is substantially in-phase with the corresponding periods of the other yarns.

15. A product as defined in claim 10 which is tubular in form.

References Cited in the file of this patent UNITED STATES PATENTS 487,857 Rood Dec. 13, 1892 2,859,506 Slayter Nov. 11, 1958 2,881,504 Billion Apr. 14, 1959 2,988,867 Quittner June 20, 1961 2,990,671 Bunting et a1. July 4, 1961 3,022,566 Daniels et a1 Feb. 27, 1962 

1. THE PROCESS FOR UNITING A WRAP OF YARNS INTO A NETWORK STRUCTURE WHICH COMPRISES INDIVIDUALLY FALSE TWISTING THE YARNS OF THE WRAP INTERMITTENTLY ALONG THEIR LENGTHS TO PROVIDE TWIST LIVELY PORTIONS OF CORRESPONDING TWIST ALONG ADJACENT YARNS, AND CONTACTING TWIST LIVELY PORTIONS OF YARNS ALTERNATELY WITH THOSE OF ADJACENT YARNS IN A PROGRAMMED SEQUENCE TO UNITE THE WRAP INTO A UNITARY STRUCTURE BY A NETWORK OF INTERTWISTS BETWEEN PORTIONS HAVING TWIST CORRESPONDENCE. 